The present invention relates to a self-propelled agricultural working machine.
Publication EP 1 321 025 A1 discloses a self-propelled agricultural working machine designed as a combine harvester with an automatic control unit for regulating the forward-travel speed. The control unit changes the forward-travel speed to control the throughput of the combine harvester and is activated as soon as a layer-thickness detector detects the arrival of crop material in a conveying device of the combine harvester.
Publication DE 10 2004 059 543 A1 submitted by the present applicant makes known a self-propelled agricultural working machine with which the ground speed is regulated using a forward-travel regulator as a function of different operating situations and based on different driving strategies. The advantages and mode of operation of regulating ground speed using a forward-travel regulator are described in the German patent application mentioned above, so their features are incorporated via reference in this application.
Investigations in practical application have shown that a ground-speed control using a forward-travel regulator in order to control the throughput of the self-propelled agricultural working machine is limited by different crop-material parameters and/or working parameters of the working machine. For example, when crop-material stands are very thin, the throughput quantity would decrease, and the forward-travel regulator would inevitably increase the ground speed. To ensure the driving stability and, therefore, the safety of the working machine, the working machine may only be operated at a certain maximum speed when it is performing work. When the increase in ground speed reaches the maximum permissible working speed, the forward-travel regulator is unable to increase the ground speed further. Since the operator of the working machine now notices that the desired throughput does not correspond to the current target throughput, he will attempt to modify the working parameters of the working machine in accordance with the current throughput to prevent a negative effect on the working result. To do this requires a great deal of technical knowledge on the part of the operator, however. In addition, the maximum permissible working speed is only one of a plurality of limiting features for the ground-speed control using the forward-travel regulator. The operator is therefore faced with the problem of not knowing which working parameters of the working machine he should advantageously modify in order to obtain an optimum working result.